A Case of Anaplastic Pancreatic Cancer with Osteoclast-like Giant Cells and Repeated Pancreatitis that was Dificcult to Diagnose Preoperatively

Abstract

Anaplastic pancreatic cancer is a very rare invasive pancreatic ductal carcinoma, accounting for only 0.1% of all pancreatic cancers. Anaplastic pancreatic cancer has a very poor prognosis and often forms a large mass when detected. A case of anaplastic pancreatic cancer with osteoclastic multinucleated giant cells, which was difficult to diagnose preoperatively on imaging, is reported. A 51-year-old woman underwent detailed examination for repeated episodes of acute pancreatitis. During the investigation, computed tomography (CT), magnetic resonance cholangiopancreatography (MRCP), and endoscopic ultrasound (EUS) showed dilatation of the main pancreatic duct in the pancreatic tail and a cystic lesion of approximately 6 mm, but no tumorous lesions were identified. Aspirated pancreatic duct cells cytology was Class III, and PET-CT showed accumulation in the pancreatic tail. SPACE showed no malignant findings. A definitive diagnosis of malignancy could not be established. Given the inability to rule out malignancy and for diagnostic and therapeutic purposes, laparoscopic distal pancreatectomy was performed for suspected pancreatic cancer. Histopathology showed anaplastic pancreatic cancer with osteoclast-like giant cells. Postoperative chemotherapy (TS-1) was administered for half a year. The patient remains alive without recurrence at one year.